The semi-gantry crane is a kind of crane between the bridge crane and the gantry crane. The semi-gantry crane has only one leg. The other end of the crane is mounted on the crane beam of the factory like a bridge crane. The track is commonly called the sky track, and the running track on the ground is called the earth track. The semi-gantry crane hoisting mechanism, trolley running mechanism and bridge structure are basically the same as the bridge crane. Due to the large span, the crane operating mechanism mostly adopts the separate driving mode to prevent the crane from causing the skewing operation to increase the resistance and even the accident. In order to prevent the wind from sliding or tipping over, the wind gauge and the interlocking with the running mechanism are installed. Crane rail clamp. Semi-gantry cranes are generally electric hoist-type cranes, so the rated lifting capacity is usually less than 16 tons.